Liver Cancer

What is liver cancer?

Liver cancer starts in the liver. To understand liver cancer, it helps to know something about how the normal liver looks and works.

About the liver

The liver is the largest organ inside the body. It lies under your right ribs, just below the right lung. The liver is shaped like a pyramid and is divided into right and left lobes.

 

Unlike most other organs, the liver gets blood from 2 sources. The hepatic artery supplies the liver with blood that is rich in oxygen. The portal vein carries nutrient-rich blood from the intestines to the liver.

You cannot live without your liver. It has many vital jobs:

  • It breaks down and stores many of the nutrients absorbed from the intestine.
  • It makes some of the clotting factors needed to stop bleeding from a cut or injury.
  • It makes bile that goes into the intestine to help absorb nutrients.
  • It filters out and breaks down toxic wastes in the blood, which are then removed from the body.

Because the liver is made up of different types of cells, many types of tumors can form in the liver. Some of these are cancer and some are not. Tumors that are cancer are called malignant. The medical word for tumors that are not cancer is benign. These tumors have different causes and are treated different ways. The outlook for your health or your recovery (prognosis) depends on what type of tumor you have.

Benign liver tumors

Benign tumors can sometimes grow large enough to cause problems. But they do not go into nearby tissues or spread to distant parts of the body. If they need to be treated, they can usually be cured by removing them with surgery. Please call us if you want to know more about the different kinds of benign liver tumors.

Cancers that start in the liver

Hepatocellular carcinoma (HCC)

This is the most common form of liver cancer in adults. It begins in the hepatocytes, the main type of liver cell. About 4 out of 5 cancers that start in the liver are this type. HCC can have different growth patterns.

  • Some start as a single tumor that grows larger. Only late in the disease does it spread to other parts of the liver.
  • Others seem to start in many spots throughout the liver, not as a single tumor. This is most often seen in people with ongoing liver damage (cirrhosis) and is the most common pattern seen in the United States.

Doctors can figure out the subtypes of hepatocellular cancer by looking at the cancer under a microscope. Most of these subtypes do not affect treatment or the patient’s outlook. But one rare type, called fibrolamellar, can have a better outlook (prognosis) than other forms of liver cancer.

Bile duct cancer (cholangiocarcinoma)

Bile duct cancers account for 1 or 2 out of every 10 cases of liver cancer. These cancers start in the small tubes (called bile ducts) that carry bile to the gallbladder. They are often treated the same way as HCC. For more information on this type of cancer, please see our document Bile Duct (Cholangiocarcinoma) Cancer.

Cancers that begin in blood vessels in the liver (angiosarcomas and hemangiosarcomas)

There are rare cancers that start in the cells lining the blood vessels of the liver. These tumors grow quickly. Often by the time they are found they are too widespread to be removed. Treatment may help slow the disease, but these cancers are usually very hard to treat.

Hepatoblastoma

There is a very rare kind of liver cancer that is usually found in children younger than 4 years old. About 2 out of 3 children with these tumors have good outcomes with surgery and chemotherapy, although the tumors are harder to treat if they have spread outside of the liver.

Secondary liver cancer

Most of the time when cancer is found in the liver it did not start there, but started somewhere else (like the colon, breast, or lung) and spread to the liver. This is called metastatic cancer. Even though these cancer cells are in the liver, they still look and act like cancer cells from the part of the body that they came from. If someone has lung cancer that has spread to the liver, the cancer cells in the liver are still lung cancer cells, so the person will be treated for metastatic lung cancer.

To learn more about cancer that has spread to the liver, please see Advanced Cancer, as well as the document on the specific place where the cancer started.

The rest of the information here refers only to hepatocellular cancer (HCC).

 

What are the risk factors for liver cancer?

A risk factor is anything that affects a person’s chance of getting a disease. Different cancers have different risk factors. Some risk factors like smoking can be controlled. Others, like a person’s age or family history, can’t be changed. But risk factors don’t tell us everything. Having a risk factor, or even several, does not mean that a person will get cancer. And some people who get the disease have few or no known risk factors.

Risk factors for liver cancer

Gender

Men are more likely to get liver cancer than women. Much of this could be because of some of the behaviors listed below.

Race/ethnicity

In the United States, Asian Americans and Pacific Islanders have the highest rates of liver cancer, followed by American Indians/Alaska Natives and Hispanics/Latinos, African Americans, and whites.

Chronic viral hepatitis

Worldwide, the most common risk factor for liver cancer is long-term (chronic) infection with hepatitis B virus (HBV) or hepatitis C virus (HCV). These infections lead to cirrhosis and are common in many parts of the world. In the United States, hepatitis C is the more common cause of liver cancer, while in many other countries, hepatitis B is more common. These viruses can spread from person to person through sharing dirty needles (such as in drug use), unprotected sex, or childbirth. They can also be passed on through blood transfusions, but this is very rare in the United States since the start of blood product testing for these viruses. People with hepatitis A or hepatitis E infection do not have an increased risk of liver cancer.

Heavy alcohol use

Alcohol abuse is a leading cause of cirrhosis in the United States, which in turn is linked with an increased risk of liver cancer.

Cirrhosis

Cirrhosis is a disease in which liver cells are damaged and replaced with scar tissue. This can often lead to cancer. In the United States, the major causes of cirrhosis are alcohol abuse and hepatitis B and C. Non-alcoholic fatty liver is a disease in which people who don’t drink alcohol develop a fatty liver. People with a type of fatty liver called non-alcoholic steatohepatitis (NASH) might go on to develop cirrhosis. There are other causes of cirrhosis as well.

Obesity

Being very overweight increases the risk of getting liver cancer. This is most likely because it can result in fatty liver disease and cirrhosis.

Type 2 diabetes

Type 2 diabetes can increase the risk of liver cancer. This is more common in people with diabetes who also have other risk factors such as obesity, heavy drinking, and/or chronic hepatitis.

Inherited metabolic diseases

Certain inherited metabolic diseases can lead to cirrhosis. People with hemochromatosis absorb too much iron from their food. The iron settles in tissues throughout the body, including the liver. If enough iron builds up in the liver, it can lead to cirrhosis and liver cancer. There are also other rare diseases that increase the risk of liver cancer.

Aflatoxins

These cancer-causing substances are made by a fungus that can get into peanuts, wheat, soybeans, ground nuts, corn, and rice. Long-term exposure to aflatoxins can increase the risk of liver cancer. In the United States and Europe, these foods are tested for aflatoxins.

Vinyl chloride and thorium dioxide (Thorotrast)

These chemicals are risk factors for some types of liver cancer. They have become much less important since Thorotrast is no longer used, and exposure to vinyl chloride is strictly controlled.

Anabolic steroids

These male hormones are used by some athletes to increase their strength. Long-term use can slightly increase the risk of liver cancer.

Arsenic

Drinking water that comes from wells in some places can have arsenic in it. This increases the risk of liver cancer and is a concern in some parts of the United States.

Tobacco use

Some studies have found a link between smoking and liver cancer, but this has been hard to study because people who smoke are also more likely to drink alcohol. The link between smoking and liver cancer seems to be strongest among people with viral hepatitis or who drink a lot of alcohol.

 

How is liver cancer found?

Liver cancer often does not cause symptoms until it is in its later stages, so it is seldom found early. Small tumors are hard to find by physical exams.

Screening tests are not advised for people at average risk for liver cancer, but they may be done in people at high risk.

Tests that may be done to find liver cancer

Many patients who develop liver cancer have had cirrhosis for a long time. If a patient with cirrhosis gets worse for no known reason, doctors should suspect that liver cancer may be the cause and do the tests needed to find out if this is the case.

AFP test

Liver cancers can sometimes be found using a blood test for a protein called AFP (alpha-fetoprotein). It is normal for AFP to be found in the blood of unborn babies, but it goes away shortly after birth. When it is found in the blood of adults, they may have liver cancer (or another kind of cancer).

Tests for AFP may be used to look for early tumors in people at high risk for liver cancer. Some tumors, though, do not make much of this protein. So by the time the AFP is high enough to be found, the tumor may be too large to be removed or may have spread outside the liver. Some liver diseases that are not cancer can also raise AFP levels. For these reasons, AFP blood tests are not advised for everyone.

Ultrasound

Ultrasound is a test that uses sound waves to make pictures of organs inside the body. For an ultrasound, you lie on a table while a wand is moved around on the skin over the part of the body being looked at. Ultrasound is sometimes used in people with certain liver cancer risk factors to help find cancers earlier. Any masses (tumors) seen in the liver can then be tested for cancer if needed.

Who should be tested?

People at higher risk for liver cancer may be helped by screening. (Screening is testing people for a disease before they have symptoms.) Many doctors recommend testing for certain high-risk groups. These include people with cirrhosis, especially if it is so bad that the patient is waiting to get a liver transplant. Otherwise a cancer may start during the wait and become so advanced that it can’t be cured. Having liver cancer may also move the person up on the transplant waiting list.

Some people with chronic hepatitis B infections should also be screened, like those with liver cancer in the family. For other people at higher risk, the benefits of screening may not be as clear. If you think you are at high risk for liver cancer, talk to your doctor about whether screening is a good idea for you.

Symptoms of liver cancer

Most of the time liver cancer does not cause symptoms in the early stages. The symptoms below could be caused by liver cancer. They can also be caused by other cancers or conditions. Still, if you have any of these problems, see a doctor right away.

  • Weight loss (when you’re not trying to lose weight)
  • Lack of appetite
  • Feeling very full after a small meal
  • Nausea or vomiting
  • Fever
  • A swollen liver or a mass that can be felt under the ribs on the right side
  • A swollen spleen, felt as a mass under the ribs on the left side
  • Pain in the belly or near the right shoulder blade
  • Swelling in your belly (abdomen)
  • Itching
  • Yellowing of the skin and eyes (jaundice)
  • Swollen veins on the belly that can be seen through the skin
  • Becoming sicker if you have chronic hepatitis or cirrhosis

Some liver tumors make hormones that act on organs other than the liver. These hormones may cause:

  • High blood calcium levels that can cause nausea, confusion, constipation, weakness, or muscle problems
  • Low blood sugar levels, which can make you feel very tired or faint
  • Breast enlargement and/or shrinking of the testicles in men
  • High counts of red blood cells which can cause someone to look red and flushed
  • High cholesterol levels

These findings may cause doctors to suspect a disease of the nervous system or other problems, rather than liver cancer.

Tests to get a better look at liver cancer

If you have any symptoms or if there is any reason to suspect liver cancer, your doctor will use one or more tests to find out if you really have the disease. You will have a physical exam, and your doctor will ask you questions about your health. Some of the tests that may be done are described below.

Imaging tests

These tests create pictures of the inside of your body. They may be done to help find tumors that might be cancer, to learn how far cancer may have spread, or to help find out if treatment is working.

Ultrasound: This test is used to find tumors in the liver. Sound waves are used to make a picture of the inside of the body. Most people know about ultrasound because it is often used to look at a baby during pregnancy. This is an easy test to have. You lie on a table, a gel is put on your skin, and a kind of wand is moved over your belly (abdomen).

CT scan (computed tomography): A CT scan uses x-rays to take many pictures of your insides. The pictures are then put together to show images of slices of the part of your body being studied. CT scans can give precise information about the size, shape, and place of any tumors in the liver or other places.

CT scans take longer than regular x-rays. You need to lie still on a table while they are being done. During the test, the table slides in and out of the scanner, a ring-shaped machine that surrounds the table. You might feel a bit confined by the ring you have to lie in while the pictures are being taken. Spiral CT (also known as helical CT) is now used in many medical centers. This type of CT scan uses a faster machine and gives pictures with more details.

You may also have an IV (intravenous) line through which you get a dye. This helps better outline structures in your body. Some people are allergic to the dye and get hives or, rarely, problems like trouble breathing and low blood pressure. Be sure to tell the doctor if you have any allergies or have ever had a problem from any dye used for x-rays. You may also be asked to drink 1 to 2 pints of a liquid that helps outline the intestine so that it is not mistaken for tumors.

MRI (magnetic resonance imaging): MRI scans can be very helpful in looking at liver cancers. Sometimes they can tell a benign tumor from one that is cancer. They can also be used to look at blood vessels in and around the liver and can help show if liver cancer has spread to other parts of the body.

MRI scans use radio waves and strong magnets instead of x-rays to take pictures. A computer makes the pattern of radio waves into a detailed picture of parts of the body. MRI scans take longer than CT scans. You may be inside a large tube-like machine for the scan, which some people do not like. Newer, more open MRI machines can sometimes be used instead.

Angiography: Angiography is an x-ray method used to look at blood vessels. A dye is put into (injected) an artery before the x-rays are taken. The dye outlines the blood vessels on the pictures, showing which ones take blood to the liver cancer. This can help surgeons decide whether the cancer can be removed and, if so, how best to plan the operation.

This test can be uncomfortable because a tiny tube (catheter) has to be threaded from the groin up into the liver artery. Usually drugs are used to make the area numb before this is done.

Angiography may also be done with a CT or MRI scanner. These are often used instead of x-rays because they can outline the blood vessels in the liver without the need for a catheter in the artery.

Bone scan: A bone scan can help look for cancer that has spread to bones. Doctors might not order this test unless you have symptoms such as bone pain, or if there’s a chance could have a liver transplant to treat your cancer.

For this test, a small amount of low-level radioactive substance is put into a vein. The substance settles in areas of damaged bone throughout the entire skeleton over the course of a couple of hours. You then lie on a table for about 30 minutes while a special camera detects the radioactivity and creates a picture of the skeleton. Bone changes appear as “hot spots” on the skeleton. This may suggest the cancer has reached the bones, but other bone diseases can also cause the same pattern. To find out for sure, other tests such as plain x-rays or MRI scans, or even a bone biopsy might be needed.

Other methods

Other types of tests may be done if your doctor thinks you might have liver cancer but the imaging test results can’t tell for sure.

Laparoscopy: In a laparoscopy the doctor uses a thin, lighted tube with a tiny camera on the end to look at the liver and other organs. The tube is put in through a small cut (incision) in the front of the belly (abdomen). This can help the doctor in planning surgery or other treatments. Also, doctors can use small instruments through this tube to take out tissue samples to be looked at under the microscope (see biopsy below).

This test is done in the operating room. You will be given drugs to make you relaxed or asleep during the test. You should be able to go home after you recover.

Biopsy: Other tests can suggest that you may have liver cancer, but sometimes the only way to be sure is to take out a piece of the tumor and look at it under a microscope. This is called a biopsy. (But in some cases, such as in people with cirrhosis whose CT or MRI tests show a liver tumor that is most likely cancer, a biopsy may not be done.)

There are different ways to get the tumor sample. In some cases, a biopsy sample may be taken during surgery that is meant to treat the tumor. Another option may be to place a hollow needle through the skin in the belly (abdomen) and into the liver to get a small biopsy sample. The skin where the needle is placed is first numbed. Biopsy samples can also be taken during laparoscopy (see above), when the doctor looks at the surface of the liver and takes samples from any areas that look abnormal.

Lab tests

Blood tests can be done to check for a substance called AFP (alpha-fetoprotein). AFP levels are often high in people with liver cancer. Doctors can compare the AFP levels before and after treatment to see how well the treatment is working.

Other tests can also help the doctor learn how well the part of your liver that is not affected by cancer is doing, and how well your other organs are working. This information can help doctors decide whether surgery is an option for you.

 

How is liver cancer treated?

This information represents the views of the doctors and nurses serving on the American Cancer Society’s Cancer Information Database Editorial Board. These views are based on their interpretation of studies published in medical journals, as well as their own professional experience.

The treatment information in this document is not official policy of the Society and is not intended as medical advice to replace the expertise and judgment of your cancer care team. It is intended to help you and your family make informed decisions, together with your doctor.

Your doctor may have reasons for suggesting a treatment plan different from these general treatment options. Don’t hesitate to ask him or her questions about your treatment options.

Making treatment decisions

After liver cancer is found and staged, your doctor will talk to you about treatment options. Choosing a treatment plan is a big decision. Take time and think about all of your choices.

You may have different types of doctors on your treatment team. These doctors may include:

  • A surgeon: a doctor who treats diseases with surgery.
  • A radiation oncologist: a doctor who treats cancer with radiation.
  • A medical oncologist: a doctor who treats cancer with medicines such as chemotherapy.
  • A gastroenterologist: a doctor who specializes in treating diseases of the digestive system, including the liver.

Many other experts may be involved in your care as well, including nurse practitioners, nurses, nutrition specialists, social workers, and others.

When planning your treatment, it is important to take into account the stage (extent) of the cancer and how well your liver is working. But you and your cancer care team will also want to think about your age, general state of health, and personal preferences.

Based on these factors, treatment options may include:

In some cases, doctors may recommend more than one of these treatments.

If time permits, it may be a good idea to get a second opinion, especially from a doctor experienced in treating liver cancer. A second opinion can give you more information and help you feel more certain about the treatment plan you pick.

 

What are some questions I can ask my doctor about liver cancer?

As you cope with liver cancer and its treatment, you need to have honest, open talks with your doctor. You should feel free to ask any question that’s on your mind, no matter how small it might seem. Here are some questions you might want to ask. Be sure to add your own questions as you think of them. Nurses, social workers, and other members of the treatment team may also be able to answer many of your questions.

  • Would you please write down the exact type of cancer I have? (Some types of liver cancer have a better outlook than others.)
  • Where in the liver is my cancer? Has it spread beyond the liver?
  • What is the stage of my cancer? What does that mean in my case?
  • How well is my liver working?
  • Do I need any other tests before we can decide on treatment?
  • Are there other doctors I need to see?
  • How much experience do you have treating this type of cancer?
  • What treatment choices do I have?
  • Can my cancer be removed by surgery?
  • What do you recommend and why?
  • What is the goal of this treatment?
  • What should I do to get ready for treatment?
  • How long will treatment last? What will it involve? Where will it be done?
  • What are the risks or side effects of different treatments?
  • How will treatment affect my daily life?
  • What are the chances of my cancer coming back with the treatment you suggest?
  • What would we do if the treatment doesn’t work or if the cancer comes back?
  • What type of follow-up would I need after treatment?
  • What are my chances of survival, based on my cancer as you see it?

 

Moving on after treatment for liver cancer

For some people with liver cancer, treatment may remove or destroy the cancer. Completing treatment can be both stressful and exciting. You may be relieved to finish treatment, but find it hard not to worry about cancer growing or coming back. (When cancer comes back after treatment, it is called a recurrence.) This is a very common worry for people who have had cancer.

It may take a while before your fears lessen. But it may help to know that many cancer survivors have learned to live with this uncertainty and are leading full lives. Our document, Living With Uncertainty: The Fear of Cancer Recurrence gives more details about this.

For others, the liver cancer may never go away completely. You may get regular treatment with targeted therapy, chemo, or other treatments to try to help keep the cancer in check. Learning to live with cancer that does not go away can be hard and very stressful. It has its own type of uncertainty.

Follow-up care

If you have finished treatment, your doctors will still want to watch you closely. During these visits, your doctors will ask about symptoms, do physical exams, and order blood tests or imaging tests (like CT scans or MRIs). Follow-up is needed to watch for treatment side effects and to check for cancer that has come back or spread as well as possible side effects of certain treatments.

If you have been treated with a surgical resection or a liver transplant and have no signs of cancer remaining, most doctors recommend follow-up with imaging tests and blood tests every 3 to 6 months for the first 2 years, then tests every 6 to 12 months. Follow-up is needed to check for cancer recurrence or spread, as well as possible side effects of certain treatments.

Almost any cancer treatment can have side effects. Some may last for a few weeks or months, but others can be permanent. Please tell your cancer care team about any symptoms or side effects that bother you so they can help you manage them. Use this time to ask your health care team questions and discuss any concerns you might have.

It is also important to keep health insurance. While you hope your cancer won’t come back, it could happen. If it does, you don’t want to have to worry about paying for treatment. Should your cancer come back, our document When Your Cancer Comes Back: Cancer Recurrence can help you manage and cope with this phase of your treatment.

Follow-up after a liver transplant

A liver transplant can be very good at both treating the cancer and replacing a damaged liver. But you will need intense follow-up after treatment. Along with watching your recovery from surgery and looking for signs that the cancer may have come back, your doctor will watch you closely to make sure your body is not rejecting the new liver.

You will need to take strong medicines to help prevent the rejection. These medicines can have their own side effects, such as weakening your immune system, which can make you more likely to get infections.

Your transplant team will talk to you about what to watch for in terms of symptoms and side effects and when you need to contact them. It is very important to follow their instructions closely.

Anti-viral treatment

If you have hepatitis B or C, your doctor may want to put you on medicines to treat or help control the infection.

Seeing a new doctor

At some point after your cancer is found and treated, you may find yourself in the office of a new doctor. It is important that you be able to give your new doctor the exact details of your diagnosis and treatment. Make sure you have this information handy and always keep copies for yourself:

  • A copy of your pathology report from any biopsy or surgery
  • Copies of imaging tests (CT or MRI scans, etc.), which can usually be stored on a CD, DVD, etc.
  • If you had surgery, a copy of your operative report
  • If you stayed in the hospital, a copy of the discharge summary that the doctor wrote when you were sent home
  • If you had radiation treatment, a summary of the type and dose of radiation and when and where it was given
  • If you had chemo or targeted therapies, a list of your drugs, drug doses, and when you took them

 

What`s new in liver cancer research?

There is always research going on in the area of liver cancer. Scientists are looking at the causes of liver cancer, ways to prevent it, and ways to improve treatments.

Prevention

Researchers are looking at ways to prevent or treat hepatitis before it causes liver cancer. Research is being done to make a vaccine to prevent hepatitis C. Progress is also being made in treating chronic hepatitis with drugs that make the patient’s immune system stronger. Some believe that vaccines and better treatments for hepatitis could prevent about half of liver cancer cases worldwide.

Finding liver cancer early

Some new blood tests are being studied to see if they can find liver cancer earlier than the tests used now.

Treatment

Surgery

Newer methods are being explored to make all kinds of liver surgery safer and more effective.

Adding other treatments to surgery: Doctors are looking at ways to shrink liver cancers so that they can be removed with surgery. Early results look good, but only a small number of patients have been studied so far.

Another focus of research involves giving treatment after surgery to reduce the chances that the cancer will return.

Laparoscopic surgery: Doctors are also looking at laparoscopic surgery to treat liver cancer. Small cuts are made in the belly (abdomen) and the doctor uses long, thin tools to look at and cut out parts of the liver that have cancer. This type of surgery may result in less blood loss, less pain after surgery, and a quicker recovery. Right now, this is still an experimental treatment for certain liver cancers.

Looking at the risk of cancer coming back after surgery: After surgery, one of the biggest concerns is that the cancer might come back (recur). Knowing someone’s risk for recurrence after surgery might give doctors a better idea of how best to follow up with them. Someday this may also help them decide who needs more treatment to lower this risk.

Researchers may have found a way to do this by testing the cells in the surgery sample. They have looked at the pattern of genes in liver cells near the tumor (not the tumor cells themselves) and were able to predict which patients were at higher risk for the cancer coming back. This is an early finding that will need to be confirmed in other studies before it is widely used.

Liver transplant: Only a small portion of patients with liver cancer can be considered for a liver transplant at this time because of the strict rules they need to meet (based mainly on the size and number of tumors). Some doctors are now looking to see if these rules can be enlarged, so that people who are fairly healthy but have slightly larger tumors might also be eligible.

Even for people who are eligible, there can be a long wait before a liver becomes available. Doctors are looking at using other treatments, such as ablation, to help keep the cancer in check until a new liver is available.

Radiation treatment

The main problem with using radiation against liver cancer is that it also harms healthy liver tissue. Researchers are now working on ways to focus radiation just on the cancer, sparing the nearby normal liver tissue. Some new methods of giving radiation are being tried, such as using drugs (called radiosensitizers) that make cancers more open to radiation.

Targeted therapy

New drugs are being made that work in a different way from standard chemo drugs. These newer drugs are aimed at (target) exact parts of cancer cells.

Tumor blood vessels are the target of some newer drugs. Liver tumors need new blood vessels in order to grow. The drug sorafenib (Nexavar®), which is already used for some liver cancers that can’t be removed, works in part by keeping new blood vessels from forming. This drug is now being studied for use earlier in the course of the disease. Doctors are also looking at whether giving it along with chemo or with other targeted drugs may help it work better.

Bevacizumab (Avastin®) and other drugs that target blood vessel growth are also being studied for use against liver cancer.

Some new drugs have different targets. For instance, a drug called erlotinib (Tarceva®), which targets a protein called EGFR on cancer cells, has shown to help some people with advanced liver cancer in early studies. Other targeted drugs are being studied, too.

Chemotherapy

New forms of chemotherapy, used along with other treatments, are being tested in clinical trials. A small number of tumors respond to chemo, but chemo has not yet been shown to help patients live longer.

Virus therapy

A newer approach to treatment is the use of a virus known as JX-594. This is the same virus that was used to make the smallpox vaccine, but it has been altered in the lab so that it mainly infects cancer cells and not normal cells. It is injected into the blood and enters the cancer cells, where it causes them to die or to make proteins that result in them being attacked by the body’s immune system.

Early results against advanced liver cancer have been promising, even in patients who have already had other treatments, and larger studies of this treatment are now being done.

 

By American Cancer Society